Hermetically sealed switchboard



1948- R. K. HELLMANN 2,447,753

HERMETIGALLY SEALED SWITCHBOARD Filed July 10, 1945 3 Sheets-Sheet l INVENTOR Ban/mid fa. [fa/[mafia BY 4M, V'M

ATTORNEYS 8- 1948. R. K. HELLMANN 2,447,753

HERMETICALLY SEALED SWITCHBOARD Filed July 10, 1945 3 Sheets-Sheet 2 2INVENTOR' Ifa'nimrd l1? Hellman /Z9 WM v- M ATTORNEYS Aug. 24, 1948. R.K. HELLMANN 2,447,753

HERMETICALLY SEALED SWITCHBOARD Filed July 10, 1945 3 SheetsSheet 3INVENTOR Kim/lard If Hal/Mann BY Id M ATTORNEYS Patented Aug. 24, 19482,447,753 HERIVIETIOALLY SEALED SWITCHBOARD Reinhard K. Hellmann,Meriden, Conn., assignor to Great American Industries, Inc., Meriden,Conn, a corporation of Delaware Application July 10, 1945, Serial No.604,167

8 Claims. 1

This invention relates to a structurally and functionally improvedswitchboard and in its more specific aspects aims to provide a unit ofthis character primarily intended for use in connection with telephoneor other communication systems.

It is an object of the invention to provide a switchboard which may besubjected to abuses such as immersion in water or mud without impairingits usefulness. Moreover, the unit may be maintained in operation forindefinite periods of time even when exposed to high humidity conditionssuch that the saturation of the atmosphere would ordinarily impair thefurther functioning of the apparatus.

An additional object is that of providing a unit of this type, certainparts of which may remain as a substantially permanent assembly, whileothers are readily removable for the purpose of cleaning the varioussurfaces which have been exposed to the action of moisture, sediment,etc.

Another object is that of providing a switchboard in which the severalparts may be separated, cleaned and reassembled without the aid ofspecial tools or skills; these operations being capable of achievementeven under distracting circumstances such as would exist under serviceconditions with the armed forces.

A further object is to provide a switchboard, the interior of which maybe hermetically sealed and may remain so during regular operation.Accordingly, the mechanisms within the apparatus will be unaffected bymoisture and other factors to which the exterior of the apparatus issubjected.

Still another object is that of furnishing an apparatus of this typewhich will embody relatively few parts, each individually simple andrugged in construction; these parts being capable of assembly undervirtually quantity production methods and when so assembled providing aswitchboard operating over long periods of time with freedom from alldifficulties.

With these and other objects in mind, reference is had to the attachedsheets of drawings illustrating practical embodiments of the invention,and in which:

Fig. 1 is a face view of a switchboard or switchcontaining unit;

Fig. 2 is a transverse sectional view thereof taken along the lines 2-2and in the direction of the arrows as indicated in Fig. 1;

Fig. 3 is a view similar to Fig. 2 but showing an alternative form ofconstruction and with 2 the parts thereof in a certain predeterminedposition;

Fig. 4 is a view similar to Fig. 3 showing an alternative form ofconstruction and with the parts thereof in a position different fromthat illustrated in Fig. 3;

Fig. 5 is a transverse sectional view of a still further form ofconstruction;

Fig. 6 is a fragmentary sectional View of certain of the apparatus asillustrated in Fig. 5;

Fig. '7 is a view corresponding to Fig. 6 but with certain of the partsshifted to occupy a different position;

Fig. 8 is a fragmentary sectional View of a plug construction which maybe utilized in conjunction with or independently of the structure shownin the preceding views;

Fig. 9 is a side elevation of an alternative form of mechanism withcertain of the parts broken away to disclose underlying constructionsand other of the parts being shown in section;

Fig. 10 is a transverse sectional View of the assembly as shown in Fig.9;

Fig. 11 is a view similar to Fig. 9 but showing a still further type ofconstruction which may be provided in accordance with the presentteachings; and

Fig. 12 is a transverse sectional View taken through the apparatus asshown in Fig. 11.

With primary reference to Figs. 1 and 2, it will be seen that thereference numeral Ill indicates the panel of the switchboard and whichconveniently provides the member which closes the open face of thereceptacle or box H. A cover [2 of any desirable construction may beassociated with this receptacle or unit. When the latter is inoperative,the cover (if provided) should extend to cover the face of the panel [0and thus protect the parts associated therewith. In accordance withconventional practice, the panel [0 may be formed with sight aperturesor target openings l3 and have keys l4 extending beyond its outer face.

Also, cords 15 may extend beyond this outer face and mount plugs I6. Thelatter, in accordance with conventional practice, are capable of beingreceived by one of a bank of jacks H exposed on the outer face of thepanel and conveniently arranged above the points at which the cords l5pass therethrough.

A magneto handle 22 may extend through the face of the panel in andterminals 2| may project from the rear face of the casing. Fasteningelements 23 may secure the panel [0 in position. Gaskets or suitablewaterproof packings 24 may be disposed between the parts at points wheredanger of leakage exists. Moreover, in line with the apertures [3 atransparent sheet of waterproof material 25 may be mounted so that thetarget 26 mounted within the casing Il may be observed. The structurewhereby the key It servesto shift the target has not been shown nor willit be described in detail in that such structure may follow more or lessconventional practice.

Also, the keys M are preferably enclosed in boots 2'! which may besecured to the face of the panel and embody flexibility such that eachkey may freely be shifted. These boots, as well as the several gasketsor packings heretoforereferred to may conveniently be formed of rubberor similar material.

The interior of the receptacle and the mechanisms therein may behermetically sealed. This may be accomplished, for example, by thegaskets and packings as heretofore referred to. However, as will beappreciated, the jacks present apertures through which fluid (air,water, and solutions) may pass if the teachings of the present inventionare not followed. Therefore, the jacks H are preferably mounted on aseparatepanel l8 which latter may be secured-in position by means ofsuitable quick-detachable fasteners l9. Also, this panel i3 ispreferably provided with openings 20 adjaeent its lower edge forpurposes hereinafter brought out.

As will also beneted-in Fig. 2, the panel I8 is preferably formed with arearward extension 28 which bearsagainst the inner face of one wall of atrough portion 29-, This portion may conveniently form a part of thepanel l and is of a width equal to the height of thesub-panel l8. Whileon this ubject, it will also be noted that, as shown in Fig. 2, the edgeof the sub-panel may be slightly flared'to provide what might be termeda wedge structure assuring a firm seating of the parts with respect toeach other such that no play will come into being between these parts.Leads such as have been indicated at 3llmay be connected to a mountingstrip 3I-secured to the base of the trough' 29.

Each of the jacks I! may have any desired number of terminals. Theseterminals are connected by, for example, jumpers 32'tocontact springs33. lE'he-Iatter are secured to the panel I 8 or to a mounting stripassociated therewith. Eachof these springs-with the-sub-pan-el IS inposition-engages with a contactplate or element 3 conveniently mountedby the-panel 3! secured to-the trough .29. Under certain conditions andas will hereinafterbe more particularly pointed out, a greater orlessernumber of contact plates 34 --rnay be employed. As will also be noted atthis time, thedetails of wiring extending from each of the terminals ofthe jacks or other parts of the apparat-ushave not been shown. Thisiswith a view-to avoiding unnecessary confusion in the illustration. Thedetails of such wiring are wellknown to those skilled in the art and mayreadilybevisualized With a construction such as that heretoforedescribed, it Wil1 be appreciated that a unit is provided whichwillf'urni-sh an enclosure such that moisture, water, silt and otherharmful elements may not enter the interior of the casing l-l-. Suchelementsespecially with the plugs not mounted within the jacksmay,however, enter-the trough 29.- This cannot be avoided if,- for no otherreason than the fact thatthe opening defined by the jacks permit of suchentrance. However,

moisture will readily drain through the openings 20. If the accumulationof moisture is such, or the presence of foreign substances additional towater prevents the proper operation of the jacks, then all that anoperator has to do i release the fastening elements l9. Thereupon, thesub-panel !8 may be withdrawn from .the trough.

With such withdrawaltof the panel t8, the contact springs move out ofengagement with the plates 34. It will be observed, however, thatmoist-ure cannot enter the main part of the casing H through the face1of the trough. The operator may now flush or otherwise clean .theelements exposed'on the rearface of the panel 18. Also, he may similarlyclean the interior of the trough 29. Thereupon, the panel may again bepositioned within the;tr,o ugl'i;.- Automatically, with suchpositioning, the circuits established by engagement of the springs 33and plates 34 will again be completed. The parts may now be operated bysimply inserting the plugs asrequired into the jacks and, as willbeappreciated, the structure of-the latter will be in all sensesconventional, if this is de sired; In anyevent; they will present nodelicate wiringproblem or maintenance technique such as would be thecase if their contacts and springs were provided as-part. of a specialstructure designed to prevent theen'trance of foreign elements into theinterior of the, trough. In fact, in the case of severe, accumulation offoreign material andafter the sub-panel IBxhas been removed, a unit suchas a wire or' pipe cleaner may be employed to, free the apertures orbores of the jacks from; any accumulation of sediment;

With respect to the quick-detachable and automaticconneetion, providedby the insertion of the panel l8 -in the trough or similar portion ofthecas-ing attention is directed, to Fig. 3. This figureshows what is inmany respect a preferred form of construction. As will be noted, a pairof jacks 35--have been indicated in'this View. In orderto avoidconfusion, only a single terminal or sprin er. thisjaekhas been, shownas connected incompletetcircuit. To that terminal there is attached. ajumper 36,,connected to av spring plateor finger 3,1;which is engageablewith the terminal or;- plate-38,, The latter, through a waterprooflead-in, is connectedto a lead 39; The spring finger 31 maybe supportedupon a mounting strip 'Mtwhich has .i'tsinner,v endbeveled or undercut.Thisface cenvenientlycooperates with a support or. cam, secured totheinner face of the trough 29 It is apparentthat, as thepanelv l8-issecured iii/position and accordingly shifted inwardly with in thetrough, the strip 40 will engage against the supporter cam,.4.l ,toforce the fingers 31 into engagement. with the. -terminals;38. Thus, acire cuit will be established in. an entirely positiveanddesirablemanner. Conversely, upon. the parts beng shiftedoutwardly,thefingers 31 would readily befree'd, from theterminals 3 8.so that nobindn f the part ma u As also shown in this view, the rod 42 which mayserve to reset the target or actuate any other desirable portion-of theapparatus is disposed in line with an opening in the upper face of thetrough. This opening --is sealed by means of a diaphragm 43 of propermaterial and-which may centrally mounta bearing element engageable withthe rod 42. This bearing element has been indicated-bythereference-numeral Maud is engaged by a similar-bearing elementmounted by one arm ofabell' cranklever id. The opposite arm 46 ofthislever may becontactable with a portion of the plug 16insertableintothe jack.

(not shown) attached to the rod.

in Figs. 2 and 3. Thus,

.It therefore follows that at this point there is also serve to actuateany desired mechanisms within the receptacle. To secure such actuation,either a rod similar to rod 42 may be employed or a different type ofactuating member may be utilized.

This connection, as shown in Fig. 4, will, however, readily permit of athrust being imparted by the bell crank lever 45, and incident to theinsertion of the plug, to the rod 42. The latter, in shifting, willserve to operate the mechanism As soon as the plug has been withdrawn,the parts will re turn to their normal positions incident to theprovision of the spring 44. The latter, obviously, need not necessarilybe employed where gravity itself will assure that the partsautomatically assume their initial positions.

As also shown in Fig. 4, it is apparent that many alternative forms ofelectrical coupling may be provided over and above those illustrated asshown in this View, the lower jack has, secured to it a mounting strip48. A spring finger 49 is suitable connected to one of the terminals ofthe jack assembly and bears against the contact plate 50. The mountingstrip 48 may, in effect, include a divided body presenting a channel iinto which the strip or terminal extends when the parts are in theirnormal position. The outer edge of one arm of the mounting strip 48 maybe beveled as indicated at- 52 to present a cam surface. The lattercooperates with the strip 50 as the parts are shifted to their seatedposition and in order to assure that the strip will be shifted into firmcircuit-maintaining engagement with the finger 49. Again, by means ofthis structure, an assembly is provided which may, without difficulty,be detached.

A further alternative form of structure is shown in Fig. 5. This has theadded advantage of permitting definite permutations of circuits to beselected. More particularly, as will be seen in this view, the referencenumeral l8 again indicates the sub-panel which, in this instance, isprovided with a rearward extension 53. The terminals of the jack 59 areconnected by jumpers or leads 54 with contacts 55. The latter aresupported by the extension 53. The sub-panel I8 is, in this form ofconstruction, conveniently of a width less than the trough portion 29.The space intervening the edge of the panel and the adjacent surface ofthe trough portion may be filled by a mounting strip 56. The lattersupports spring contacts or fingers 51. These bear respectively on theterminals 55 and terminals 58, which latter connect with the interior ofthe easing of which this assembly forms a part.

As shown especially in Figs. 6 and 7, certain of the spring fingers orcontacts 51 may be provided with extensions 59 Assuming that the partsare disposed in the manner shown in Fig. 7, it will be noted that one ofthe terminals 58 is not engaged by any of the spring fingers 51. We mayassume that this terminal is, for example, connected to a buzzer orsimilar unit. Therefore, with no circuit being completed, that unit willbe rendered inoperative. If, on the other hand, the strip 56 iswithdrawn, reversed and re-inserted in position as shown in Fig. 6,

the particular terminal will be engaged by the extension 59. Therefore,the circuit will be completed. Consequently, any unit such as a buzzerconnected thereto will be energized.

A structure such as this is useful in many different associations. Forexample, and especially where the switchboard may be employed by thearmed forces, it might be desirable to utilize the apparatuswithout anybuzzer or other unnecessary acoustical effect being present. Therefore,by simply withdrawing the panel [8 and the strip 56, the parts may bereassembled with the latter in the position indicated in Fig. "I. Thiswill produce the desired result. By simply withdrawing and reversing thepositon of the strip, the circuit through the buzzer or other unit mayagain be re-established.

Finally, referring to Fig. 8, it will be noted that a plug l6 has beenindicated which is insertable through the bore or opening of a jack 60.The shank of this plug has secured to it a cup member 6| preferably ofrubber. The edges of this cupmay bear within an annular groove 62concentrically disposed with reference to the aperture of the jack. Thenormal tension of the cup will be such that the base portion will not bebulged. However, when associated with the mounting panel as in Fig. 8,the overall length of the side walls of the cut may be adequate toassure that these side walls will be slightly compressed, thus bulgingthe base of the cup. Consequently, a sealing contact is establishedbetween the cup and the panel. This is especially pronounced if a groovesuch as 62 is employed. Thus, in effect, a stopper structure isprovided.

This will be especially valuable if the plugs are inserted into thejacks at the time that the switchboard assembly is intended to beinoperative and, for example, transported from one locality to theother. If the drain openings 20 are dispensed with under thesecircumstances and even if the switchboard is immersed, an entrance ofwater or other foreign material through the apertures of the jacks willbe prevented. Consequently, it will-except under most extraordinarycircumstances-be unnecessary to dismount the panel ill for purposes ofcleaning the space defined by the interior of the trough as well as theparts secured to the rear face of the panel.

In certain types of apparatus it may not be desirable to provide atrough portion. In fact, in many layouts it might be preferred toproduce a hermetically sealed receptacle or switchboard in which thepanels or surfaces did not include a relatively recessed part. In orderto illustrate the application of the present teachings to such types ofconstructions, attention is invited to Figs. 9 to 12 inclusive.

In these views, the reference numeral 63 indicates the panel or surfaceof the receptacle and 64 a cover removably mounted by the latter. In theform of construction shown in Figs. 9 and 10, the cover is movedlaterally or parallel over the surface of the panel in order to mountthe the former on the latter. Therefore, a retaining flange or clip 65may be mounted by the panel to receive the extended portion 66 of thecover 64. The cover may carry any suitable number of jacks 61 whichreceive plugs 68 to, for example, actuate the switch structure 69 bytheir stems 10. Also, these stems may serve to shift actuators 11mounted by diaphragms I2. The latter serve to seal the openings 13against the entrance of fluid and foreign material. A member to beactuated such as, for example, a rod 14 may be disposed adjacent theactuator 1|.

Preferably mounted upon a di-electric block 15 Within the cover 64 areterminals 16 having extensions 11 which latter embody resiliency.Contacts 18 are mounted by the panel 63 and, by means of suitablebacking structures, the entrance of fluid and materials into theinterior of the receptacle is prevented despite the fact that thesecontacts extend from the exterior to the interior of the latter. Asuitable securing unit 19 may serve to retain the cover 64 in mountedposition above the panel 63.

With a structure such as the foregoing, it will be appreciated that anoperator, by simply loosening the securing unit 19 may slide the cover64 ,over the surface of the panel and away from the recess provided bythe clip or flange 65. When the cover once clears this structure, it maybe moved in a direction transverse to and away from the panel 63.Conversely, the cover may be mounted by following a reverse procedure.Under such procedure, it will be apparent that no damage will occur tothe parts because a mere wiping engagement will be all that can followas a consequence of the application of the cover to the panel. In otherwords, the terminals and especially the extensions 11 thereof willmerely wipe against the adjacent faces of the contacts 18 as the coveris shifted into position. Likewise, the par-ts are so arranged that theactuator 1| will not come into engagement with portions of themechanisms as supported by the cover and as the latter is being mounted.However, when the stem of the plug is inserted in the jack-, the latterwill be caused to function. Also, if the actuator H is present, theinsertion of the stem will cause the actuator to engage the unit 14 tobe operated. This will be permitted as a consequence of the flexibilityof the diaphragm 12.

,The structure shown in Figs. 11 and 12 contemplates that the cover willbe moved in a plane perpendicular to the panel in order to mount theformer on-the latter or detach it therefrom. .Securing devices such as80 may be employed. Again, jack structures 8| are associated with thecover and contacts 82 which have their bodies connected with a leadwithin the interior of the receptacle are exposed on the exterior of thepanel surface where the cover is to be mounted. These contacts areengaged by terminals 83 which again are of preferably resilient oryielding type. A-conventional and suitable switch mechanism 84 may forma part of the jack and to be operated by the stem 85 of the plug '86. Alever 81 may be pivo'tally supported by the ja-ck'structure and serve toengage an actuating portion or area of a flexible sealing member suchas.the diaphragm 88'. The-latter, in t urn,,may serve to act against andshift a rod 89 or other uitable operating unit.

In this form of construction, it willbe apparent that, in common withthe structure shown in Figs. 9 and 10, a supplemental receptacle is, ineffect, provided and the interior of which may readily be cleaned. Inthis connection, it will be appreciated that drain openings (not shown)but as previously described may form a part of the housing 64. Theinterior of the mainreceptacle or switchboard maybe hermetically sealedunder all normal operating conditions. Simply by moving the housing asshown in Figs. 1-1 and 12 towards the panel 63 and securing itimposition, the necessary electrical connections are established.

8 Also, the apparatus is set up so that if mechanical connections are tobe provided these are also automatically established.

Thus,- among others, the several objects of the invention asspecifically afore noted are achieved. Obviously, numerous changes inconstruction and rearrangements of the partsm-ight be resorted towithout departing from the spirit of the invention as defined by theclaims.

I claim:

1. A telephone switchboard including in combination a casing formed witha sight opening to the rear of which an indicator unit is positioned,means whereby said unit may be restored to a non-indicating condition,.a' receiving surface forming a part of said casing, said casing andsurface being formed to prevent the entrance of fluid into said casing,terminals within the area of said surface and electrically connectedwith the interior of said casing, a jack, means for mounting the latterto extend adjacent said surface, means for connecting said jack withsaid terminals, actuating means manipulatable from the exterior of saidcasing, and means interposed between said restoring means and actuatingmeans and providing a fluid-tight connection such that the functioningof said actuating means will cause an operation of said shifting means.

2. A telephone switchboard including in combination a substantiallywaterproof casing, wall members forming a trough portion inside saidcasing and in substantially fiuidtight relationship thereto, terminalsdisposed within said trough portion and connected .to the mechanismWithin said casing, a mounting member adapted to be disposed adjacentsaid trough portion, apertured jacks supported by said mounting member,and means for connecting said jacks with said terminals.

3. A telephone switchboard including in combination a substantiallyfluid-tight casing, wall members forming a trough portion inside saidcasing and in substantially i-luidtight relationship thereto, terminalsdisposed within the area of said trough portion and connected to themechanism within said casing, a mounting member adapted .to be disposedadjacent said trough portion, apertured jacks supported by said mountingmember, means for connecting said jacks with said terminals, and saidmounting means presenting an opening through which accumulations ofmaterials between said member and trough porti-on may drain.

4.'A telephone witchboard including in combination a substantiallyfluid-tight casing, wall members forming a trough portion inside saidcasing and in substantially fluidtight relationship thereto,terminals-disposed within said trough portion and connected to themechanism within said casing, a mounting member adapted to be disposedadjacent said trough portion, apertured jacks supported by said mountingmember, and quick-detachable connecting means functioning automaticallyupon said member being extended into said trough portion to electricallyconnect the jacks with said terminals.

5. A telephone switchboard including in combination a substantiallyfluid-tight casing, wall members forming a trough portion inside saidcasing and in substantially fiu'idtigh't relationship thereto,terminalsdisposed within the area of said trough portion and connectedto the mechanism Within said casing, a mounting member adapted to bedisposed adjacent said trough portion, apertured jacks supported by saidmounting member,

quick-detachable connecting means functioning automatically upon saidmember and extending inside said trough portion to electrically connectthe jacks with said terminals, and said connection comprising springfingers and plates engageable by said fingers.

6. A switchboard including in combination a substantially fluidtightcasing, a mounting surface forming part of said casing, terminalsextending from the face of said surface, a switchmounting paneldisposable adjacent said surface, terminals mounted by said panel, astrip disposable adjacent said panel and terminals, contacts carried bysaid strip and extending from opposite faces thereof, the contacts atone of said faces being adapted to engage all of the correspondingterminals and the contacts at the other face being adapted to engageonly a selected number of the corresponding terminals, and the saidstrip being adapted to be reversed so as to electrically connectdifierent permutations of said two sets of terminals.

'7. A switchboard including in combination a substantially fluidtightcasing having a trough portion, terminals extending from the inner faceof said portion forming part of said casing, a switch-mounting paneldisposable across said portion, terminals mounted by said panel, a stripinterposed between the terminals mounted by said panel and the terminalsextending from the face of said portion, different permutations ofcontacts carried by said strip, and means for securing said panel andstrip with reference to said switchboard and whereby the strip may beoptionally reversed to connect difierent permutations of the terminalscarried by the panel with terminals carried by the trough portion.

8. In a telephone switchboard, in combination, walls forming asubstantially fiuidtight casing, an aperture disposed in one of saidwalls, a flexible seal extending across said aperture and adapted toseal the same against the entrance of fluid and foreign matter; a rigidcontact member peripherally supported by said seal and in fluid tightrelationship thereto and relatively movable, normally spaced elements,forming a composite actuating mechanism, the latter elements beingdisposed at opposite faces of said flexible seal and being adapted toenter into relative engagement through the intermediary of said rigidcontact member.

REINHARD K. HELLMA'NN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,779,058 Borgmann et al Oct. 21,1930 1,809,025 C-ruser June 9, 1931 2,334,901 Bullerjohn Nov. 23, 1943

